Adjusting Pump Timing

adamdrives · #1 08-06-2016, 12:47 PM

Hey All, searched around but can't find a post that deals with the problem I'm having.

I'm in the process of restoring an '85 740 gle with the d24t motor. Right now, I am stuck trying to correctly time the injection pump. My timing was too high, so I slackened the three (I can only find 3, afaik this is correct) bolts and tried to "tilt" the pump outwards. I'm not sure if this should be easy, but the pump feels as if it's completely stuck. Finally using a prybar, I was able to gently rock the pump against the block, and it moved. Now, the timing is far too low, and I don't have any safe surfaces to pry against to try to tilt the pump inwards.

What can I try next? The three bolts and mating surfaces have all been soaked with penetrant. I'm leery about getting my torch out near a fuel source, that would normally be my course of action near stuck surfaces. Any ideas? I have also cracked loose the high pressure lines thinking they might be creating some tension on the pump. Thanks in advance.

Adam

Goteborg Vapenfabrik · #2 08-07-2016, 05:36 AM

Moving the injection pump with anything other than force you can apply with both hands may over tighten the injection pump belt. There is a better method using tools 5199 and 5201. Make sure the engine is at TDC by looking for the mark on the flexplate or flywheel. Using tool 5199 to hold the rear camshaft sprocket, loosen the nut holding the rear camshaft sprocket on the camshaft. The torque value is 73 ft lbs here, it's very tight. Tool 5201 is used with a 1/2" drive bar or ratchet to loosen the nut. Loosen the nut, keeping in mind that it's very tight. Once it is loose, retighten finger tight. You are now going to rotate the sprocket in the normal direction of rotation ( the camshaft must remain stationary). Rotate the sprocket with tool 5199 or your hand, keeping in mind that you are rotating the injection pump belt and the sprocket on the injection pump. While you are rotating the camshaft sprocket, watch the needle on the dial indicator, once you reach the value you are looking for, tighten the rear camshaft sprocket nut , making sure your injection pump timing stays in the right place. Once you have the nut tight enough it won't move get ready to retorque to 73 ft lbs, this is much torque for a hard to reach area. This method takes rotating the injection pump by hand out of the equation. Makes sure your injection pump timing belt is not too tight. Address that first before setting the injection pump timing.

Goteborg Vapenfabrik · #3 08-07-2016, 05:43 AM

Keep tool 5201 and the torque wrench at a right angle while applying torque to the rear camshaft sprocket nut.

Goteborg Vapenfabrik · #4 08-07-2016, 10:43 AM

The camshaft sprockets are fastened to the camshaft by screws, the inside of the camshaft being internally threaded, not nuts as I wrote in my reply. Good luck with your restoration.

adamdrives · #5 08-07-2016, 07:00 PM

Thanks for that info, everything worked exactly as you described. Luckily the car came with a number of the diesel specific tools, I was able to get the timing into spec on the first try. I had trouble cracking the 21mm bolt on the end of the cam, but with the hood in the full up position it was much easier. Thanks again!

Unfortunately the car still doesn't start. There are a few different issues that are apparent now that I have been able to crank the car. There is a fuel leak somewhere on the underside of the injection pump towards the back of the motor. I am going to try snugging all the high pressure lines on the pump I cracked loose when I was trying to get the pump free again, but they already feel pretty tight. This area seemed to get wet after I cleaned the entire pump with parts cleaner to try to find the source. I will try tightening them again with two flare wrenches, one to counterhold the fitting out of the pump and one on the line nut. I hope that solves the leak issue. Other than that, the glow plug indicator lamp doesn't come on. Greenbook says to look for power from orange wire at control unit, I get nothing, so I will have to look more deeply into that. I also can't find a wiring diagram for what I believe is a coolant temp sensor somewhere near the rear cam sprocket. I remember having a hard time removing a connector from back there, but now can't find any connections. Either way, it's a relief to finally have the pump timed and the wiring harness (almost) installed. Hopefully tomorrow I will make more progress. Thanks again for your detailed responses.

Goteborg Vapenfabrik · #6 08-08-2016, 07:48 AM

Without glow plug function on at least five out six, there's not much chance it will start. Also, regarding the main engine wiring harness, its eight wires , there may be a diagram for the engine wiring at k-jet.org. Haynes manuals for the 740 have a diesel engine wiring diagram. The sensor at the rear of the head is the temperature sensor for the glow plug system. A brown wire goes to it. This is also probably the best time to check all six glow plugs. You can get number six out by removing the rear timing belt cover and working gingerly from behind the head. Have a telescoping magnet ready to position the known good glow plug for reinstallation. Getting the tiny 8mm nut on glow plugs five and six to secure the bus bar isn't much fun either. Once you have verified correct timing, glow plug function and fuel, the only thing left is compression. Hope it won't come to that.

adamdrives · #7 08-08-2016, 03:23 PM

I resolved the glow plug issue, I made a mistake when I re-wired the glow plug relay. As far as I can tell, the glow plugs are operational.

The car still doesn't start, but I have a new concern. The PO stated that he was selling the car because the turbo seized (this was true, but the wiring harness was also disintegrated). I rebuilt the turbo, but now I'm wondering if there could be an oil pressure issue that caused it to fail in the first place. With the oil feed bolt cracked on the turbo, there is no visible oil pressure when cranking the car. I checked the banjo bolt, and it looks clear, as does the feed line as far as I can see. When/If I am able to get the car running, I'd prefer to know that my oil pressure is ok, especially to the turbo.

My plan is to replace the oil filter, as that could create a restriction, and check/replace the oil pressure bulb in the dash, which does not come on. Other than that, is there anything simple I can look for? The oil level is ok.

Goteborg Vapenfabrik · #8 08-08-2016, 04:28 PM

These engines don't generate oil pressure instantly. The engine will need to start for it to pick up the oil enough to build oil pressure.

ngoma · #9 08-10-2016, 08:24 PM

Quote:

Originally Posted by adamdrives

Finally using a prybar, I was able to gently rock the pump against the block, and it moved.

Not a good way to time the IP. Good possibility of cracking the high pressure injector hardlines, or pre-stressing them for future breakage. If you must rotate the IP, loosen all the hardlines first, then retighten them afterwards, not too tight (16 ft-lbs? Check the forum or greenbook for exact spec) to not deform the fittings.

This post has a better method of timing the IP. There are others here on the forum. We need to make a sticky for IP timing.

http://www.d24t.com/showpost.php?p=6253&postcount=16

adamdrives · #10 08-11-2016, 04:51 PM

Quote:

Originally Posted by Goteborg Vapenfabrik

A malfunctioning cold start device should not prevent it from starting. Double check the alignment marks on the injection pump sprocket and the injection pump bracket. If they are way off at TDC, you willing need to rotate the camshaft sprocket in the manner described previously. You could be off a full millimeter, too far or not far enough.

The alignment marks from the injection pump to the pulley? They are very close. A millimeter or two off could be an issue?

Quote:

Originally Posted by ngoma

Not a good way to time the IP. Good possibility of cracking the high pressure injector hardlines, or pre-stressing them for future breakage. If you must rotate the IP, loosen all the hardlines first, then retighten them afterwards, not too tight (16 ft-lbs? Check the forum or greenbook for exact spec) to not deform the fittings.

This post has a better method of timing the IP. There are others here on the forum. We need to make a sticky for IP timing.

http://www.d24t.com/showpost.php?p=6253&postcount=16

Yes, I was able to get the correct timing by loosening the camshaft bolt as discussed on previous page.

I'm concerned that I may have damaged the threads from over tightening the hard line connections. if I'm not able to stop the leak, I'm not sure what my options would be. All I can think of is trying to remove the lines and get silicon tape around the fittings.

I did more fault tracing in the pre-heating circuit, and found that all six glow plugs are dead. i'm not sure if this is unhappy coincidence or the result of me grounding out the strap to glow plugs against the head when I was fooling around with a pry bar

Either way, the replacements are on their way so I will hopefully be able to try again this weekend. Any tricks for getting out #6 glow plug? I had to practically crouch on the battery to gain access.